Dina Mitchell said she had owned her Fitbit Flex 2 for about two weeks when the fitness tracking device allegedly caught fire on her arm Tuesday night.

"I was literally just sitting and reading when my Fitbit exploded,” Mitchell told ABC News in an emailed statement Sunday. "It was either defective or really mad I was sitting still so long … I don’t know. Either way, it burned the heck out of my arm."

When the device began to burn, Mitchell said she ripped it off her arm and tossed it on the floor. She told ABC News that her doctor had to pick pieces of plastic and rubber out of her arm after the incident.

An emergency care provider in the Milwaukee area told KTRK that Mitchell was treated the day after she said the incident occurred.

Mitchell, who said she got the tracker as a birthday gift, said Fitbit offered her a free replacement device after she notified the company.

A Fitbit spokesman told ABC News that the company is investigating the issue. The company said it was unaware of any other similar complaints.